if the phone has 'hardware' voice activated dialing, not sprint's voice command, you will be able to place a call using the call/end button on your bluetooth headset.

this is impossible with sprint's voice command because you have to dial *2 before you say the name. this means that you will have to press buttons on your phone, then press the call/end on the headset, and say name.

the treo 600 not having voice activated dialing seems to be a step backwards in the technology race.

p.s. i have downloaded the sdk. i am working on voice dialing. but i don't have a treo600. please bear with me until i acquire one.

Not sure if this works on Treo 600, but on my Treo 300, I have configured most excelent TreoHelper application to dial '*' when pressing headset button. It behaves exactly as you describe. I press and hold headset button, TreoHelper dials '*' and connects me to Sprint Voice Command. No other buttons.